Not long ago I wrote that the danger President Trump faces from the various investigations into the Trump-Russia matter had changed dramatically in recent weeks. Now, in just the last few days, the situation has changed even more. In five ways:

1. The Mueller office: Investigative arm of the House

The Washington Post reported recently that special counsel Robert Mueller is investigating the president for possible obstruction of justice. The possibility of Trump facing legal jeopardy raises the question that has been part of every big Washington scandal involving the White House: Can a sitting president be indicted? The generally agreed-upon answer is no; impeachment is the constitutional remedy when presidential misconduct rises above a certain level. That is what would happen with Trump, if it came to that.

So what is Mueller doing, as far as the president himself is concerned? The special counsel is known to be investigating a number of figures around Trump for possible charges not related to the 2016 election. Those figures could certainly be indicted if the evidence warrants. But as far as the investigation into alleged Trump obstruction is concerned, Mueller's work will end up not in an indictment, but in the House of Representatives. The House is constitutionally charged with originating articles of impeachment. But it does not have the investigative powers of the Justice Department and, if impeachment is on the table, will rely on the evidence Mueller gathers. Which makes Mueller's office, for the purposes of Donald Trump specifically, not a prosecutor's office but the investigative arm of the House.

2. Mueller's team of killers vs. Trump's amateurs?

Recently a Republican lawyer who supports the president and has experience in government emailed an article he had read about the team of prosecutors Mueller is assembling. "This ain't good," he headlined the email, which went on to discuss the legal stars Mueller has hired.

Contrast that, he said in a later conversation, to the Trump team, led by Trump personal lawyer Marc Kasowitz and including partner Michael Bowe and Washington legal veteran Jay Sekulow. "I look at this team and think this is a joke!" the lawyer said.

The reaction is not unusual. As far as experience in criminal prosecutions is concerned -- the kind of experience that specifically relates to the issues in the Trump-Russia case -- the Mueller team has a huge advantage over the Trump team. In that sense, the coming legal fight could be asymmetrical warfare.

3. Clinton-style attacks on the prosecutor?

Some Trump supporters, most notably Newt Gingrich, have begun to attack Mueller. Still, at this early date it's clear that, when it comes to attacking prosecutors, TrumpWorld has much to learn from the last president who found himself in deep legal and political trouble, Bill Clinton.

Clinton and his supporters made an art out of attacking federal prosecutors. The president's surrogates accused independent counsel Kenneth Starr and the prosecutors who worked for him of misconduct, of leaking, of bias, of all sorts of unprofessional behavior. Clinton's lead defense attorney, David Kendall -- the kind of deeply experienced Washington fighter Trump could use now -- took Starr to court over leaks, while the president's other surrogates slammed the prosecutors every day on television.

In other words, when things got serious, Clinton and his team went to the mattresses against federal law enforcement. And it worked. It is in no way clear that Trump could pull off the same thing -- Clinton had a much more favorable media environment, with some in the press happy to join in the attacks on Starr -- but a war on the prosecutor may be his only option.

4. An ever-expanding investigation

Just what Trump-related subjects is Mueller investigating? A better question right now might be what Mueller is not investigating. There has been talk of looking at allegations of money laundering in the Trump circle. And looking at the president's conversations with a wide variety of people -- not just members of his administration, but friends and whoever Trump might have talked to in his nighttime call sessions. And looking at Michael Flynn's business arrangements with Turkey, Russia and other places. And Paul Manafort's business and finances. And perhaps even the Holy Grail of NeverTrumpism: the president's tax returns. And, oh, the allegation that used to be at the core of the case, that Trump or his associates colluded with Russians to try to influence the 2016 election. The point is, Mueller can determine the scope of the investigation, and if Washington history is any guide, investigations tend to expand, not contract.

5. The Comey 'what if'

A key lesson emerged from the recent testimony of Attorney General Jeff Sessions before the Senate Intelligence Committee: Without the president's decision to fire FBI Director James Comey, the Trump-Russia investigation would be on a downward trajectory. The collusion charge would be fading for lack of evidence. Investigators would be going down side roads involving Flynn and Manafort in which the public would have little interest. And congressional investigators might even devote most of their attention to the Russian interference itself, which is the serious issue at the bottom of this whole thing. The political radioactivity of the issue would be ticking down, not up.

But not after Comey. At the Sessions hearing, Democrats had nothing new on collusion. They barely seemed interested. Instead, they focused to a great extent on trying to get Sessions to reveal what the president did or did not say in private discussions -- about Comey. On the Democratic side of the hearing -- and much of the Republican side, as well -- the issue was Comey, Comey, Comey. In the end, it could be that the president's impatience to get rid of Comey in order to shorten an investigation that he believed to be going nowhere resulted in a new investigation that could last the rest of Trump's time in office.